The Class Action against Zoetis, the pharmaceutical company responsible for manufacturing and marketing the Hendra vaccine, has commenced in the Federal Court of Australia as researchers announce they have identified a new strain was the cause of a previously unexplained horse death in September 2015.

The Class Action has been brought by horse owners who registered their details with the law firm LHD Lawyers against Zoetis who manufactures and markets the Hendra Equivac HeV vaccine.

Since its release in 2012, the Equivac HeV vaccine has been administered to more than half a million horses throughout Australia.

The focus will be on the marketing and promotional material Zoetis produce, with the applicant alleging the company “made representations including; There was a serious risk of horses contracting Hendra virus in all areas of Australia in which flying foxes were present; The vaccine had no serious side-effects; and all horses in Australia should be treated with the HeV vaccine.”

Class members  also allege that from 10 August 2012 to 20 March 2018 their horses suffered side effects from the HeV vaccine and as result, suffered loss or damage, including “diminution in the financial value of the horse, veterinary treatment expenses, loss of income generated by the horse, loss of opportunity to gain income from the horse and the replacement value of the horse.”

A sample class member, has also been identified in relation to a claim that the HeV vaccine was not of an “acceptable quality” within the meaning of section 54(2) of the Australian Consumer Law.

Zoetis denies any wrongdoing or liability.

Hendra virus (HeV) is a zoonotic disease (can pass from animals to humans) that is carried by flying foxes, passes on to horses and then to humans.

Whilst the likelihood of horses or humans contracting the disease remains very low, it can produce life-threatening illness, which has no cure or specific treatment. HeV is a notifiable disease and is found exclusively in Australia, although health authorities in other countries are keeping an eye on its close relation, the Nipah virus which has the ability to spread from person to person and is deadlier and more infectious than Ebola. Both Hendra and Nipah viruses were classified as potential bioterrorism agents after 9/11.

The incubation period for HeV, from infection to onset of symptoms may vary between 5 to 16 days, and onset is sudden, with rapid deterioration.

Signs vary from case to case, as the virus can affect different parts of the body, but includes fever, depression, lethargy, increased heart rate, laboured breathing, frothy nasal discharge, discomfort/weight-shifting between legs, sweating, muscle weakness, spasms or twitching, wobbly gait, balance difficulties, weakness, lethargy, circling, loss of coordination, head-pressing, convulsions and collapse, urinary incontinence and colic. Death usually occurs within 48 hours. HeV should be considered with the sudden death of an otherwise healthy horse.

The disease is only transmitted to people through very close contact with secretions or bodily fluids of infected horses. An infected horse can excrete HeV through nasal discharges for up to 72 hours before clinical signs appear, mortality is 70% and diagnosis is based on veterinary blood tests and swabs.

Vaccination of horses is considered crucial to break the cycle of HeV transmission from flying foxes to horses and then to people, as it prevents both the horse developing the disease and passing it on. It also protects horses from shedding the virus.

Hendra Virus was first identified in 1994 in the stable of Vic Rail a 49-year-old racehorse trainer. This first outbreak infected 20 horses, 13 of them died or were so sick they had to be euthanised. Rail himself became ill and died within a week of feeling unwell.

Since then, more than 100 horses are known to have been infected. 7 people have contracted Hendra Virus from attending to sick horses and four of them have died, the most recent in 2009. Evidence of exposure to Hendra Virus has been identified in asymptomatic dogs on two occasions.

Last week, researchers from the Australian led research project ‘Horses as Sentinels’ identified a new strain of Hendra Virus. The newly recognised variant has not been detected previously by routine biosecurity testing in horses and shares approx. 99% sequence identity with the 2015 horse case strain.

In addition, the new strain has been detected in grey-headed flying fox samples from Adelaide in 2013. Partial sequences of the variant have also been detected in flying foxes in other states. Grey-headed flying foxes migrate and their range includes parts of southern Australia, which previous advice classed as low risk – with some interpreting this to mean negligible risk of Hendra virus spillover.

Up until now, the original strain of Hendra virus has only been known to occur within the range of black flying foxes and spectacled flying foxes.

The ‘Horses as Sentinels’ research team has developed updated tests capable of identifying the new strain, and will be sharing them with relevant laboratories. They have also established that the current Hendra virus horse vaccine is expected to be equally effective against the new strain.